To form a corrugated plate by the stamping without generating cracks even when the stock is hard and thin, or its valley is deep.

A corrugated face 16b is formed inclined on the upper surface of a lower die 16. An elastic die 19 whose lower surface 19a is the horizontal plane is provided on an upper die 17. During the stamping, the center part of the stock 11 is pressed by a pressing plate 18 to lower the elastic die 19. The elastic die 19 holds the stock 11 between the corrugated face 16b of the lower die 16 and itself while it is elastically deformed to form a corrugated plate 12. Due to the inclination of the corrugated face 16b, the peak part of the corrugation is successively formed on the stock 11 one by one. The tensile stress generated in the stock 11 at one time is reduced thereby. As the forming is advanced, the material is successively shifted from the outer side which is the free end side of the stock 11, and no cracks are generated.